Organosilicon polyamide compositions and method of making same



2,8 ,1 a ORGANOSILICON POLYAMIDE COMPOSITIONS 7 AND METHOD OF MAKING Leonard M. Shorr and Mary P. David, Pittsburgh, Pa., assignors to Dow Corning Corporation, Midland, -,aoon tion of ch No Drawing. N Application February 21, 1955 Serial N0. 489,778

Claims (CL 260-42) invention relates to silicone modified polyamides of the nylon type, a

It has long been known that organosilicon compositions could be employed to modify organic resins and that they have been successfully incorporated in many type resins such as alkyds, epoxy resins, polyesters and vinylic resins. However, to date no commercially feasible method has been devised for incorporating organopolysiloxanes into nylon-type polyamides. This has been due to two reasons. One is the lack of satisfactory organosilicon intermediates for reacting with the polyamide-type resin and the other has been the unsatisfactory properties obtained by merely blending organosiloxanes wtih polyamides.

The present invention obviates these difficulties in that it pertains to a copolymer of polysiloxanes and polyamides in which the siloxane is actually tied to the amide chains through amide linkages. Because of this actual chemical combination the properties of the resulting products show substantial improvement over the polyamides alone.

It is the object of this invention to produce polyamides of the nylon type which have improved physical properties. Another object is to improve the adhesion of polyamide resins to glass and metal. Other objects and advantages will be apparent from the following description.

Thi in n i n r t o th con ensation P o u t. of from .1 to 34% by weight of a siloxane of the formula Yooo OH: T

in which Y is alkyl or hydrogen, R is a monocyclic aryl hydrocarbon or a lower alkyl radical, n has a value from 0 to 2 inclusive, R is a monovalent hydrocarbon or halogenated monovalent hydrocarbon radical, m has an aver- 7 age value from 1 to 3 inclusive and a has a value from 0 to 5.66 inclusive and 66 to 99.1% by weight of a condensation product of an al pha i diamin n an liph tie dibasic a id,

The products of this invention are prepared in the conventional method for preparing polyamide resins, i, e., the silicone, the amine and the dibasic acid are heated together at temperatures above 100 C. with the removal of volatiles. In general, for the purpose of, this invention it is immaterial what the order of addition of the re, actants is, i. e., the siloxane carboxylic acid or siloxane ester may be first reacted with an excess of amine in order to give the corresponding amides having free amino groups and the resulting intermediate then reacted with the dibasic acid. Alternatively, the dibasic acid may be reacted with an excess of the diamine and subsequently the product reacted with the siloxane, or all three ingredients may be reacted simultaneously. In general, the relative proportions of the three reactants will be such that there is an approximately equivalent number of amino gr up nd carbo y roups n the ea ion mix- 2,823,195 Patented Feb. 11, 1958 2 ture. Ideally the number of amino groups and carboxyl groups should be equal.

The silioxanes employed in the compositions of this invention may be materials in which each silicon atom has. one of the carboxy endomethylene radicals attached thereto. These siloxanes may be of three classes, namely,

and

B 8101.5 SlO where Y and R are as above defined, and 3c; is an integer of from 0 to 2 inclusive.

In a di ion, the siloxanes empl yed in this invention may be copolym rs of any one or any om ina ion of the above-defined siloxane units with siloxane unitsjof the formula R' SiO in which R and m are as above defined. This. type of siloxane may be present in amount up to 85. mol percent of the total siloxane employed in the composition. The second type of siloxane canbe composed of units or any combination of units oi the formula R'SiO R' SiO and R' SiO together with limited amounts of SiQ units. For the purpose of this invention R" can be any monovalent hydrocarbon radical such as alkyl radicals such as methyl, ethyl, propyl and octadecyl; alkenyl radicals such as vinyl, allyl and hexenyl; cycloaliphatic radicals such as yolohexyl and cyclo exeny ary hyd ocarbon ad c such as p y yl. and Xeny a d allsary ydro arbon radicals such as benzyl and halogenated monovalent hydrocarbon radicals such as chlorophenyl, bromoxenyl, a,a,a-trifluorotolyl trifluorovinyl, tetrafluoroethyl and chlorotrifiuorocyclobutyl,

The siloxanes of this invention having the carboxy endomethylene radical attached to the silicon are prepared in accordance with the method described in the copendns appl cat o at John .L- Sp er Seria o- 63,062, led October 18, i 54, n w Patent N 2,72 ,98 issued o em e 1 B fly, th s m d omprises the r ac on of he compounds th hydr gen con ai ing h r si nes su h a riohloros l e, methy diohl s n tc-r, her by e ilane adds ac s the ou le nd- The r lting pro c is han hydrolyzed to give the siloxanes. These siloxanes may be copolymerized with hydrocarbon and halogenated hydrocarbon substituted siloxanes in the conventional manner.

ground into a powder and molded into test bars at a pressure of 2800 p. s. i. at 250 C. for 20 minutes. properties of each sample are shown in the table below:

The

Compositions in parts by weight Rockwell Flexural Modulus Percent Hardness Strength, of Elas- Elonga- Hexa- Adlpic R Scale p. s. i. tlcity tion in Siloxane methylene Acid Flex iamine Commercial nylon-- 118 8, 820 1. 69X10 1. 8 1.9- 9. 5 10. 95 111 17. 200 2 78X10 10. 4 9. 5 10. 22 110 14, 800 1. 89X10 14. 9. 8. 76 118 7, 210 2X10 14. 2

It is preferred, although not essential, that the slloxanes Example 2 of this invention be completely condensed with respect to silanol hydroxyls prior to use in the compositions of this invention. This condensation is accomplished by refluxing the hydroxylated siloxane in solution with an alkyline catalyst until condensation is complete.

For the purpose of this invention improved results are obtained when the siloxane is employed in amount from .1 to 34% by weight of the total product. If the weight of the siloxane exceeds 34%, there is a sharp deterioration in the physical properties of the resulting product.

Any aliphatic diamine may be employed in this invention. This includes such materials such as ethylene diamine, hexamethylene diamine and octadecylene diamine. The preferred amines are those having 6 carbon atoms.

Any aliphatic dicarboxylic acid can be employed in the process of this invention. This includes such acids as malonic, succinic, adipic, suberic, sebacic, maleic and dimethylmaleic acids.

It is to be understood that a combination of 2 or more amines or 2 or more acids or 2 or more of the defined siloxanes can be employed in the compositions of this invention.

The products of this invention are useful in the preparation of polyamide laminates, molding compositions, and fibers. They are particularly useful in the preparation of polyamide glass laminates due to their superior adhesion to glass. The compositions of this invention are also useful in the making of molded articles due to their superior fiexural strength.

The following examples are illustrative only and are not to be construed as limiting the invention which is properly delineated in the appended claims. The symbols Me and Ph are used throughout the specification to represent methyl and phenyl radicals respectively.

Example 1 The reactants employed in the various runs of this example were a siloxane of the formula HOOC-- CH1 hexamethylene diamine and adipic acid. The reactants were employed in the proportion shown in the table below and each reaction was carried out in the following manner. The siloxane acid was dissolved in a 70% aqueous solution of hexamethylene diamine. The adipic acid was added and stirred until a homogeneous aqueous solution resulted. The solution was then heated to a temperature of 120-130 C. as nitrogen was passed through. After all the water had been removed, the essentially dry product was heated under nitrogen to a maximum temperature of 250 C. until evolution of water had ceased and the material was in the form of a fused hard polymer. The resulting product was then A resinous material was obtained by reacting 6.45 parts by weight of a copolymer having the composition 55 mol percent phenylmethylsiloxane, 15 mol percent monophenylsiloxane, 15 mol percent monomethylsiloxane and 15 mol percent of MeOOC-- CH:

first with 9.86 parts by weight hexamethylene diamine and then with 12.4 parts by weight adipic acid following the procedure of Example 1. A moldable resin resulted.

Example 3 Equivalent results are obtained when 3.8 parts by weight of the siloxane Me SiO H0 08- OH:

9.5 parts by weight hexamethylene diamine and 10.22 parts by weight adipic acid are reacted in accordance with the procedure of Example 1.

Example 4 Equivalent results are obtained when 6 parts by weight of a copolymer of 50 mol percent 5 mol percent vinylmethylsiloxane, 15 mol percent monophenylsiloxane, 15 mol percent monoamylsiloxane and 15 mol percent Ph sro -YOOC- on, 2

in which Y is selected from the group consisting of hydrogen and alkyl radicals, R is of the group consisting of monocyclic aryl hydrocarbon and lower alkyl radicals, n has an average value from 1 to 2 inclusive, R is of the SiOm HOOC CH:

and from 66 to 99.1% by weight of the condensation product of hexamethylene diamine and adipic acid.

3. An organosiloxane-polyamide copolymer which is the condensation product obtained from the reaction of an intimate mixture of from .1 to 34% by weight of a siloxane in which the polymeric units are of the formula SiO HO 0 atrium L and from 66 to 99.1% by weight of a condensation product of hexamethylene diamine and adipic acid.

4. A composition comprising an organosiloxane-polyamide copolymer which is the condensation product obtained from the reaction of an intimate mixture of (1) a siloxane in which the polymeric units consist essentially of from to 100 mol percent inclusive of units of the formula in which Y is selected from the group consisting of hydrogen and alkyl radicals, R is selected from the group consisting of monocyclic aryl hydrocarbon and lower alkyl radicals, and x is an integer of from 0 to 2 inclusive; and

from 0 to mol percent inclusive of units of the formula R,,,Si0, T

where R is selected from the group consisting of monovalent hydrocarbon radicals and halogenated monovalent hydrocarbon radicals, and m is an integer of from 1 to 3 inclusive, (2) an aliphatic diamine, and (3) an aliphatic dibasic acid containing only carbon, hydrogen and oxygen atoms; the proportions being such that prior to condensation there is from 0.1 to 34 percent by weight inclusive of (1).

5. A method for the preparation of organosilicon polyamide copolymers comprising reacting (1) a siloxane in which the polymeric units consist essentially of from 15 to mol percent inclusive of units of the formula SlO 3- Yooo i111:

in which Y is selected from the group consisting of hydrogen and alkyl radicals, R is selected from the group consisting of monocyclic aryl hydrocarbon and lower alkyl radicals, and x is an integer of from 0 to 2 inclusive; and from 0 to 85 mol percent inclusive of units of the formula References Cited in the tile of this patent UNITED STATES PATENTS 2,516,030 Swiss July 18, 1950 

1. A COMPOSITION OF MATTER COMPRISING AN ORGANOSILOXANE-POLYAMIDE COPOLYMER WHICH IS THE CONDENSATION PRODUCT OBTAINED FROM THE REACTION OF AN INTIMATE MIXTURE OF FROM .1 TO 34% BY WEIGHT OF A SILOXANE OF THE AVERAGE GENERAL FORMULA 